Synvisc/Orthovisc Coverage on Medicare Advantage

I have a frantic customer who is screaming at me because Aetna Specialty Rx wants to charge him $509 for this injection. However, when I look up these rx on different formularies (Humana, United & Aetna), these are either NOT LISTED or t reads that these are covered under Part B. They are injectables after all. This irate customer tells me that this same rx was covered before at the doctor's office without issue and not much costs. I find that a little hard to believe. Does anyone have experience with how they bill this on an MA plan? I imagine that it's 20% even though the man says diff

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